The saxitoxins are neurotoxins and are among the most potent non-protein toxins known. There are several thousand cases of paralytic shellfish poisoning worldwide each year with a case- fatality rate approaching 10%. Since there is no antidote for such poisoning, avoidance of contaminated material is the only means of control. The currently accepted method of detecting saxitoxin and its natural derivatives is by mouse bioassay. Alternative methods have been sought, but each has one or more significant drawback. Immunoassays appear to be the most promising method to date. Current limitations on immunoassays are lack of ability to detect all toxins in the saxitoxin group and problems with interference due to components in the sample matrix. Methods are proposed for generating polyclonal and monoclonal antibodies which will enable detection of all of the saxitoxins. Phase I will focus on the preparation of two different neosaxitoxin haptens and the demonstration of an immunological response in mice or rabbits. Phase II will extend the work and culminate in the development of suitable non-radioactive immunoassays. In addition to use in saxitoxin immunoassays, the antibodies produced may have additional applications as therapeutic agents in cases of paralytic shellfish poisoning.